Soluble Phenyl- or Alkoxyphenyl-Substituted Rigid-Rod Polyamides and Polyimides Containing m-Terphenyls in the Main Chain

Abstract

Diamino-5′-phenyl-or 4-alkoxyphenyl-m-terphenyl and 4,4′′-dicarboxy-5′-phenyl-mterphenyl were synthesized through pyrylium salts and used for the preparation of rigid-rod polyamides and polyimides. The polymers were characterized by inherent viscosity, elemental analysis, FT-IR, UVvis, 1 H NMR, 13 C NMR, X-ray, DSC, TMA, TGA, isothermal gravimetric analysis, and moisture absorption. It was shown that the presence of the 4-alkoxyphenyl pendent groups enhanced remarkably the solubility of polymers as well as reduced the Tg's and thermal stability. In addition, the polyamide bearing 4-(dodecyloxy)phenyl side groups displayed softening.

Synthesis and Characterization of Novel Aromatic Polyimides from Aromatic Diamine and 3,3''''',4,4'''''-p-Sexiphenyltetracarboxylic Dianhydride

“…The IR spectrum (KBr) exhibited absorption bands at 2990 cm -l (C-H), 1730 cm -l (C =O), 1420 (S= 0), and 1215 (C-F). 4.83 (35 mmol) of potassium carbonate, and 100 mL of deoxygenated N, N-dimethylformamide were added to a flask equipped with a reflux condenser. The flask was flushed with nitrogen, and 1.0 g tetrakis(triphenlphosphine)paladium (Pd(PPh 3 ) 4 were added to the reaction mixture.…”

Synthesis of High Molecular Weight Poly(m-phenylene terephthalamide) in NMP/CaCl2Solvents

“…The high melting point, high softening temperatures, and insolubility of the aromatic polymer in most organic solvents make them difficult to process [10]. This poor processability is the result of a rigid polymer backbone and the formation of intermolecular hydrogen bonds [11].…”

Rigid-rod polyamides and polyimides prepared from 4,3?-diamino-2?,6?-di(2-naphthyl)-p-terphenyl and 2?,6?,3?,5?-tetra(2-naphthyl)-4,4?-diamino-p-quinquephenyl

“…[12][13][14][15][16] Recently, new rigid-rod polymers have been synthesized in our laboratory starting from pyrylium salts. More particularly, soluble rigid-rod polyamides and polyimides have been prepared from substituted aromatic diamines of p-terphenyl [17][18][19] or biphenyl. 20 In addition, we have prepared blue light-emitting, rigid-rod polyamides and polyimides from an aromatic diamine of pquinquephenyl carrying phenyl or 4-biphenylyl side groups.…”